Linux Netfilter IPT_SO_SET_REPLACE Memory Corruption

A memory corruption vulnerability exists in the IPT_SO_SET_REPLACE ioctl in the netfilter code for iptables support. This ioctl is can be triggered by an unprivileged user on PF_INET sockets when unprivileged user namespaces are available (CONFIG_USER_NS=y). Android does not enable this option, but desktop/server distributions and Chrome OS will commonly enable this to allow for containers support or sandboxing.